GEOLOGY

Detailed explanation-1: -Declination is defined as the angle between magnetic north and the true north. However, the diagram on the topographic map sheet gives the value of the angle between magnetic north and grid north, which is referenced to the grid lines shown on the map. This angle is properly called grid declination.

Detailed explanation-2: -EXPLANATION: The axis of the Earth’s Magnetic field is inclined at an angle of about 11.3 degrees with the geographical axis.

Detailed explanation-3: -The range of dip angle is from-90 degrees at the North Magnetic Pole to +90 degrees at the South Magnetic Pole. The contour lines along which the dip is measured at the surface of Earth is referred to as isoclinic lines.

Detailed explanation-4: -Neglecting atmospheric refraction, for an observer at the equator, declination is always 0° at east and west points of the horizon. At the north point, it is 90° − ||, and at the south point, −90° + ||. From the poles, declination is uniform around the entire horizon, approximately 0°.